Rapid outdoor non-destructive detection of organic minerals using a portable Raman spectrometer

Raman spectral signatures have been obtained for a series of organic minerals using a compact portable Raman instrument equipped with 785-nm laser excitation. Well-resolved Raman spectra of crystalline salts of carboxylic acids, whewellite and mellite, as well as of the aromatic mineral idrialite were recorded. For comparative purposes, an amorphous fossil resin, baltic amber, was also investigated. The results obtained confirm that portable Raman instruments can be considered as excellent tools for field geological applications, including the detection of organic minerals in the frame of outcrops of sedimentary rocks or coal beds. Organic minerals can be added to the list of established biomarkers, including porphyrins, hydrocarbons and organic acids, which are important for the study with regard to future exobiological missions such as the ESA ExoMars mission to detect the presence of extinct or extant life on Mars. Copyright (C) 2009 John Wiley & Sons, Ltd.